[tz] zone.tab deprecation

[Paul Eggert]

On 10/16/2014 12:20 PM, Matt Johnson wrote:
> Can't we just maintain both files indefinitely?

Yes and no.  We can make changes to both when that's easy (e.g., the 
2014f changes for Russia, or the proposed changes for Bougainville) but 
some newer changes are not easily expressed in the old model and those 
changes are omitted from zone.tab (e.g., the 2014f changes for Crozet 
and the Scattered Islands, or theproposedchanges for Vietnam before 1976).

I don't anticipate zone.tab going away any time soon, but it has already 
started to drift away from being the "full" or "canonical" list, and I 
don't recommend it for new applications.